This project is concerned with measuring and understanding the mechanisms of phagocytosis by granulocytes and monocytes in normal individuals and those with hematologic disorders known to affect phagocytic cells. We plan to examine the processes of differentiation of granulocyte precursors, degranulation, ingestions, oxidative metabolism and bacterial killing. The studies on oxidative metabolism are divided into three parts: (1) the effects of metabolic and membrane perturbations on the activation and activity of the superoxide generating system of phagocytic cells and how examination of this system can be used for clinical investigations. (2) The isolation and characterization of the reduced pyridine nucleotide oxidase and the changes that occur with activation and termination of the respiratory burst. (3) The relationship between oxidative metabolism in macrophages and tumor cell killing by phagocytic cells.